N-(2-Hydroxyhydrocarbyl) Iminodicarboxylates

ABSTRACT

Novel N-(hydroxyhydrocarbyl)iminodicarboxylates or the corresponding carboxylic acids are of the formula:   WHEREIN R1 is an aliphatic hydrocarbon radical of 4 to 20 carbon atoms, R2 and R3 are divalent aliphatic or aromatic hydrocarbon radicals of 1 to 9 carbon atoms and X and Y are either hydrogen or salt-forming elements or radicals. In preferred embodiments of the invention, R1 is a saturated radical of 12 to 20 carbon atoms, R2 and R3 are identical alkylene radicals of 1 to 2 carbon atoms, and X and Y are the same monovalent metals, or lower alkanolamines e.g., sodium, triethanolamine. The novel compounds are surface active and substantive to fibrous materials such as cotton, wool and synthetics. They are useful as detergents or as components of detergent compositions. Preferred compounds function very effectively as softening agents, either alone or in conjunction with other detergent composition materials. Additionally, they may be used as starting materials for the manufacture of corresponding N-oxides, which also may be employed as detergents and textile softeners.

United States Patent [191 Sundby et al.

[451 Feb. 4, 1975 N-(Z-HYDROXYHYDROCARBYL) IMINODICARBOXYLATES [75] Inventors: Bjorn Sundby, Piscataway; Edward J. Kenney, Bernardsville; Harold E. Wixon, New Brunswick, all of NJ.

[73] Assignee: Colgate-Palmolive Company, New

York, NY.

[22] Filed: Jan. 17, 1973 [21] Appl. No.: 324,314

Related U.S. Application Data [62] Division of Ser. No. 880,992, Nov. 28, 1969, Pat. No.

Primary Examiner-Lorraine A. Weinberger Assistant Examiner-Patrick J. Hagan Attorney, Agent, or Firm-Steven J. Baron; Norman Blumenkopt; Herbert S. Sylvester [57] ABSTRACT Novel N-(hydroxyhydrocarbyl)iminodicarboxylates or the corresponding carboxylic acids are of the formula:

wherein R is an aliphatic hydrocarbon radical of 4 to 20 carbon atoms, R and R are divalent aliphatic or aromatic hydrocarbon radicals of 1 to 9 carbon atoms and X and Y are either hydrogen or salt-forming elements or radicals. in preferred embodiments of the invention, R is a saturated radical of 12 to 20 carbon atoms, R and R are identical alkylene radicals of l to 2 carbon atoms, and X and Y are the same monovalent metals, or lower alkanolamines e.g., sodium, triethanolamine.

The novel compounds are surface active and substantive to fibrous materials such as cotton, wool and synthetics. They are useful as detergents or as components of detergent compositions. Preferred compounds function very effectively as softening agents, either alone or in conjunction with other detergent composition materials. Additionally, they may be used as starting materials for the manufacture of corresponding N-oxides, which also may be employed as detergents and textile softeners.

5 Claims, N0 Drawings 1 N-(Z-HYDROXYHYDROCARBYL) IMINODICARBOXYLATES This is a divisional, of application Ser. No. 880,992 filed Nov. 28, 1969, now Pat. No. 3,725,473.

This invention relates to novel N-(Z-hydroxyhydrocarbyl) iminodicarboxylates and the corresponding iminodicarboxylic acids. It has been discovered that these compounds are useful surface active agents and are substantive to a variety of fibrous materials. Thus, they may be used as emulsifiers, solubilizing agents for lipophilic materials, wetting agents, detergents and softeners for textiles. They are also useful as reagents from which the corresponding N-oxides may be made, which oxides also possess surface active and textilesubstantive properties.

Since the introduction of commercial synthetic organic detergents and emulsifiers to replace the conventional water-soluble higher fatty acid soaps, much research work has been performed in an effort to improve such compounds and compositions including them, with the object of obtaining better and more convenient laundering of textiles. As a result, a wide variety of types of surface active agents and detergents has been produced and many such compositions have been manufactured commercially and have been introduced to the market place. As better products were made, the goals set for researchers on detergency were increased and the properties of the desired products were such as to have been thought impossible of attainment only a few years before. For one thing, although the cleaning function of surface active materials is still very important and products which clean better than competitive compounds are always in demand, additional functions of cleaning compositions and compounds were desired. For example, with the increasing importance of cold water washing, detergent compositions were desired which would be capable of successfully cleaning and whitening textiles and laundry in cold water, as well as in hot water. Such washing capability is of importance in making a product acceptable for the washing of wool and other shrink-sensitive materials. As softening agents have been introduced, consumers have accepted them and have wanted them to be easier to use than has been the case in the past. Although there is still a strong market for textile softeners which are applied in the final rinse of a washing cycle, many housewives object to having to be present to add the softener to the washing machine at that time and relatively few washing machines include devices for addition of softeners in the final rinse. Therefore, more effective softeners have been in demand, which would be capable of being added to the wash water as a part of the detergent composition and would not require a separate addition to the rinse.

The present invented compounds are useful surface active agents. They possess detergent activity in both hard and soft waters and at both elevated and lower temperatures. In addition, preferred compounds are excellent in textile softening activity, even when used in the washing, rather than the rinsing step ofa laundering operation. Such an activity evidences a high degree of substantivity, which is unexpected in a surface active material which itself functions to release adsorbed and absorbed substances from materials being washed. The compounds are also generally capable of making washed textiles and other articles anti-static. Additionally they are usually desirably low-foaming in wash water.

in accordance with the present invention, there are provided novel compounds of a formula,

which are effective detergents and which preferably also serve to soften fibrous materials when applied to them, as in aqueous solution. In the formula, R is an aliphatic hydrocarbon radical of 4 to 20 carbon stoms, R and R are divalent, aliphatic or aromatic hydrocarbon radicals of l to 9 carbon atoms and X and Y are hydrogen or a salt-forming element or radical. R and R may be the same or different and X and Y may be the same or different. If either X or Y is an element, it is preferred that it should be an alkali metal, an alkaline earth metal or other suitable salt-forming metal, capable of making the compounds water soluble. If X or Y is a radical, it is preferred that such be ammonium, alkylamine or alkanolamine, either mono-, di-, or trialkylamine or mono-, dior tri-alkanolamine, in which the alkyl and alkanol groups of the salt-forming amines are of l to 4 carbon atoms, preferably 2 to 3 carbon atoms.

In preferred embodiments of the invention, the compounds are those wherein R is an aliphatic hydrocarbon radical of 12 to 20 carbon atoms, R and R" are aliphatic alkylene radicals of l to 2 carbon atoms, and X and Y are monovalent salt-forming ions, including alkali metal, ammonium, mono-, diand tri-alkyl-amine and mono-, diand tri-alkanolamine. In such preferred compounds, it is additionally preferred that R and R are the same and that X and Y are the same.

With respect to X and Y, it will be noted that in the above formula there has been no allowance made for divalent or polyvalent salt-forming ions. Neverthless, it may be considered that X and Y stand for a monovalent portion of any salt-forming ion. Thus, if a divalent ion, such as magnesium, is employed, it could be joined to both the carboxylic groups of the present compounds or could be joined to only one of them, with another valence bond either otherwise tied up, as with a different anion, or with it joined to the carboxylic groups of different iminodicarboxylic acids. In such a way, mixed salts may be formed, as may be acid-salt compounds.

The preferred compounds mentioned above are found to be excellent as textile softeners, especially for cotton articles, which may be washed with them, even in the presence of builders, other detersive compounds and additives. They may be used in normal washing, including rinsing operations. With respect to such softening properties, the most preferred compounds are the salts of N-(Z-hydroxy-higher alkyl) iminodi-lower carboxylic acids, wherein the higher alkyl is of 14 to 22 carbon atoms and is of straight chain structure. Of such compounds, it is preferred to employ the sodium and potassium salts, with the sodium salt being that which is generally considered most useful. Of the lower carboxylic acids, the most preferred is acetic acid, so that the most preferred of these compounds are the N-(2- hydroxy-higher alkyl)-iminodiacetates.

Although the preferred and the highly preferred embodiments of the invention have been mentioned above, which compounds have exceptionally good softening activities with respect to textiles and laundry, other compounds within the scope of the present invention are also useful surface active agents, wetting agents, emulsifiers and detergents, but might not produce to the same extent the extremely desirable softening activity shown by the most preferred compounds of this invention. In fact, in some instances such compounds might be essentially ineffective as practical softeners, although they will often have the unexpected advantage of being highly useful for their detergency or other surface active properties, often in both hard and soft waters, and at elevated or comparatively low washing temperatures.

Among compounds within the scope of the formulas previously I given are N-(2-hydroxy-n-hexyl)- iminodiacetic acid, mono-n-propanolamine salt; N-(2- hydroxy-n-heptyl)-iminodiacetic acid, ditriethanolamine salt; N-(2-hydroxy-n-octyl)- iminodiacetic acid, disodium salt; N-(2-hydroxypropylene tetramer)-iminodiacetic acid, dipotassium salt; N-(Z-hydroxydodecyl)-iminodipropionic acid, dilithium salt; N-(Z-hydroxy-propylene pentamer)- iminodiacetic acid, magnesium salt; N'-(2-hydroxyhexadecyl)-iminodiacetic acid, disodium salt; N-(2- hydroxydocosyl)-iminodiacetic acid, disodium salt; N- (Z-hydroxytetradecyl)-iminodiacetic acid; N-(2- hydroxyoctadecyl)-iminodiacetic acid; N-(Z-hydroxyn-hexyl)-iminodi-n-propionic acid, monopotassium salt; N-(2-hydroxy-o-ethyl-n-decyl)-iminodi-n-butyric acid, di-diethanolamine salt; N-(2-hydroxydodecyl)- iminodi-p-benzoic acid, magnesium salt; N-(2- hydroxyhexadecyl)-iminoacetic-propionic acid, calcium salt; N-(Z-hydroxyoctadecenyl)-iminobenzoictoluic acid, diisopropylamine salt; N-(Z-hydroxyoctadecyl)-iminodipentanoic acid, mixed sodium and potassium salt; N-(2-hydroxytetradecyl)-iminodiacetic acid, monoammonium salt; N-(Z-hydroxyhexadecyU- iminopropionic-butyric acid, mono-monoethanolamine salt; N-(Z-hydroxytetradecyl)-iminobenzoic-oisopropylbenzoic acid, mixed magnesium and calcium salt; N-(2-hydroxyoctadecyl)-iminoacetic-toluic acid, mixed sodium and triethanolamine salt; N-(Z-hydroxydocosyl)-iminodiacetic acid, aluminum salt; N-(2- hydroxy-mixed higher linear alkyl of 14-16 carbon atoms)-iminodiacetic acid, disodium salt; N-(2- hydroxy-n-tetradecyl)-iminodi-n-decanoic acid, disodium salt; and N-(Z-hydroxyoctadecyl)-imino-n-pentanoic-n-heptanoic acid, mixed sodium and potassium salts.

The above-mentioned compounds are only illustrative of those within the formulas previously given and it will be clear that other compounds within the scope of such formulas are also useful and in many cases may possess properties superior to those specifically listed above. Thus, variations may be made in the above specific compounds, wherein other mentioned constituents are employed to replace those illustrated. In some cases, additional non-interfacing substituents may be employed and usually these will be present on the longer chain portions of the molecules, such as on the R group, where they do not as significantly affect the properties of the final product. Among useful substituents are amino, hydroxy, halogen, e.g., chlorine, bromine, fluorine, and hydroxy-lower alkyl, wherein the alkyl is of up to four carbon atoms. The number of such substituents present will usually be small, often no more than four per molecule and usually, less than three. It is generally preferable that the present compounds be unsubstituted but many of the substituted compounds are often of utility similar to those literally within the formulas given and therefore, are also useful. As has been illustrated by recitations of the specific compounds within the formulas given above, mixed salts may be employed as may be acid salts. Also, the salt-forming metal or other radical, if divalent or polyvalent, may be joined to both acid portions of the imino compound or a single salt-forming metal or other radical may be joined to two or more molecules of the acids of this invention.

The hydrocarbyl groups of R include both saturated and relatively slightly unsaturated groups. Thus, one or two double bonds per R are acceptable and are within the present invention, although it is preferred to employ alkyl groups as R'. Of the alkyl groups, straight chain alkyls, terminally joined to the carbon to which the hydroxyl group is attached are highly preferred and are those described herein, unless indicated differently, although those alkyl groups which are not terminally joined also possess utility, as do various alkyl groups of non-linear structure. Thus, medially joined keryl (alkyl derived from kerosene) groups may be employed for R and there may also be used various polymeric materials, such as propylene tetramer and pentamer, a pre' ferred form of which is such a mixture thereof as to average 13 carbon atoms per group.

R and R are preferably short chain alkylene, usually of l to 2 carbon atoms, but longer chain alkylenes and divalent hydrocarbyl radicals containing aromatic moieties are also useful to make detergent and softener products. Normally, the alkylenes will be present with a carbon content of the alkylene groups, R and R, of four or less but in some instances as many as nine carbon atoms may be found in such group to be good for making novel and useful surface active materials. When aromatic materials are employed, it is preferred that they be derivatives of benzene, usually with no more than two substituents on the benzene ring, in addition to joinder of the benzene ring to the rest of the present molecule.

X and Y, while they may be hydrogen, are preferably salt-forming ions. Of course, mixed substitution of hydrogen and salt forming ions is within the invention. The salts made are usually more stable and freer flowing than the acids and because the product is most frequently employed in alkaline solutions, it is therefore preferably in the salt form. Of the salt-forming ions, those which are monovalent are generally preferred, usually because of their greater water solubility, which is an important feature in the use of the present compounds in aqueous systems. However, even if water solubility is low, salts of low solubility can be employed as washing agents in other polar media and may be useful in an aqueous medium, especially if solvents or solubilizers are present.

The novel compounds of the present invention can be prepared by reacting a hydrocarbon-1,2-epoxide with an iminodicarboxylic acid. Such reactions are in accordance with the equation:

the aqueous medium, is mixed well with an approximately stoichiometric proportion of the hydrocarbonl,2-epoxide. Often, an additional solvent, such as alco-.

hol, is employed, together with heat. The product is generally separated by conventional techniques, which may include treatments with a ketone to produce an oily precipitate, deoiling of such precipitate and conversion of the residue to a crystalline solid, which may be recrystallized from an alcohol to a desired purified product.

The iminodiacids and their salts are known compounds, as are the hydrocarbon epoxides. Methods for making such compounds from readily available starting materials are also known to those of skill in the art. Ac-

cordingly, they need not be described herein. Similarly, methods for making hydrocarbon-1,2-epoxides are known, and details thereof need not be given here.

In the reaction of although stoichiometric proportions are preferred, it is within the present invention to employ an excess of either reagent, depending upon the circumstances, with the usual excess not exceeding 50 percent and rarely exceeding percent. Although the reaction may be effected at various temperatures, it is normally preferred to initiate it at approximately room temperature, e.g., l5-30C. Ordinarily, the iminodiacid reactant is dissolved in an aqueous medium and it is preferred to utilize deionized water for such medium. The proportion of water employed may be relatively small, and usually it is preferred to use from to 200 percent of the total weight of the reactants. In any case, sufficient water is employed to dissolve the iminodiacid, and the epoxide, usually as a liquid, is admixed with the dissolved reagent. Such admixing may take from 10 seconds to l hour and during mixing the temperature of the reaction mixture is held within the mentioned room temperature range. After initial reaction, the temperature is usually raised to from 50C. to l 10C., depending upon the materials being reacted. The temperature most conveniently employed is the reflux temperature of the reaction mix. The reaction mixture is held at such temperature for a period of from about 1 hour to about 42 hours, after which it is considered that the reaction is complete. After that time, a one-phase system is found, from which the product may be obtained by precipitating with a suitable lower ketone, e.g., acetone, methyl ethyl ketone, diisopropyl ketone or other ketone having one to four carbon atoms in the alkyl groups thereof. Conversion to a solid crystal form may often be effected by treatment with a lower alcohol, such isopropanol or ethanol, after which purification may be effected by recrystallization from such solvent.

The products obtained are usually white or lightcolored solids, which in some cases may have a yellow ish tinge. The solids may be somewhat hygroscopic but usually are sufficiently free-flowing to be employed, ei-

ther by themselves or with other materials, as surface active agents or softeners for textiles.

The novel compounds produced are normally utilized in aqueous solution, either alone or with additives to produce improved detersive solutions or emulsions and to act as wetting agents. They are also used in such compositions to soften fabrics, especially cotton textiles, although they also soften other fabrics, such as wool and synthetics. in some processes the invented compounds usefully wash and soften textiles in a single operation. Such activity, wherein the softening agents are effective despite being added to the wash water,

lrather than the rinse water, and wherein they themselves act to remove other substances from the fibers or laundry being washed, is considered to be unusual. Such softening effect appears to depend in significant part upon the substantivity of the invented compounds to the fibers. As a result of such dual utility, many of the present compounds are highly useful in combination detergent-softeners. The advantages of such compounds, as opposed to separate detersive and softening materials, have been recited previously.

The following examples are given to illustrate the invention but are not to be considered as limiting it. Unless otherwise stated, all parts given in the examples and elsewhere in the specification are by weight.

EXAMPLE 1 355 parts of iminodiacetic acid, as the disodium salt, are dissolved in 350 parts of water and with the resulting solution are admixed 368 parts of n-dodecane-l ,2- epoxide at room temperature (25C.), over a period of 3 minutes. Then 400 parts of normal butanol are added to the reaction mixture and it is refluxed for a period of 18 hours, with the temperature being in the range of -98C.

After the completion of refluxing, the temperature is allowed to drop and a single-phase system results. An oily residue is obtained from this phase by addition thereto of 500 parts of acetone. 65 parts of the oil are drawn off and are boiled for 1 hour with 500 parts of isopropanol. A crystalline solid settles out upon cooling to room temperature. This is separated by filtration and is recrystallized from an additional 250 parts of isopropanol. The recrystallized product obtained is a white powder with a slight yellowish tinge. it appears to be slightly hygroscopic but flows relatively freely. It is obtained in nearly stoichiometric yield, with approximately 65 parts of purified product resulting.

When, in place of the disodium salt, the salt of iminodiacetic acid employed is the dipotassium salt, the diammonium salt, the di-triethanolamine salt or the mixed sodium-potassium salt, and the same general method for manufacture described above is employed, the corresponding N-(2-hydroxydodecyl)- iminodiacetates are obtained. Of course, the stoichiometrically equivalent amounts of such iminodiacetates will be employed in such reactions. Similar results are obtained when the acid form is employed.

The procedure of Example 1 is also followed, utilizing different iminodicarboxylates, such as iminodipropionic acid, disodium salt; iminodibutyric acid, dipotassium salt; iminoaceticpropionic acid, mixed sodium, potassium salt; iminodibenzoic acid, monotriethanolamine salt; and iminodi-o-toluic acid, ditriethylamine salt, with the desired N-(2- hydroxyhydrocarbyl)-iminodicarboxylates resulting.

7 8 Corresponding products are obtained when the starting hardness water, at l20F., containing a detergent comepoxides are n-decane-l,2-epoxide; n-octane-l,2- position comprising 6.6 grams of sodium tripolyphosepoxide; n-tetradecane-l,2-epoxide; and n-hexadecphate and two grams of N-(2-hydroxyhexadecylane-l,2-epoxide. In some cases the times of reaction iminodiacetic acid, disodium salt. After washing in a are extended or the temperatures are increased to promini-basket of a General Electric Company automatic mote reaction, whereas in other instances, a shorter washing machine, the towel is rinsed in the usual way time is needed and lower temperatures are employed, and is essentially freed of water. It is then dried and as will be evident to those of skill in the art. Also, the softness is rated, on a scale of] to 10, with l indicating recovery methods utilized may be varied in specific sita towel that is not soft and 10 indicating excellent softuations to allow the production of the greatest proporl0 ness. Using such a rating system, the towel washed with tion of the purest compounds. the detergent composition containing N-( hydroxyhexadecyl)-iminodiacetic acid disodium salt EXAMP I i 2 as made following the procedure of Example 2 hereof,

The procedure of Example 1 IS follo ed x ep that is given a rating of 10+. Softening effectiveness is also 430 Parts of h-hexadecahe-liz-epoxlde are p y obtainable from the other new compounds of this ininstead of the 368 parts of H-dOdeCaHe-L -GPO vention in which R is of l2 to carbon atoms. and the refluxing is continued for 24 hours. At the end Th compounds f E ampl 1 a d Ex l 2 are of that time. the reaction miXlul'e has bC0me Water also evaluated for detersive properties. The results are soluble and a single phase is produced. The desired i di ted i Table 1,

TABLE I Spangler Soil Detergency Tests Rd (Soil Removal) N. B. tap 300 p.p.m. N. B. tap 300 ppm.

N-(Z-hydroxydodecyl)-iminodiacetic acid, disodium salt I66 I22 I52 9.l

N-(2-hydroxyhcxadecyll-iminodiacetic acid, disodium salt l5.5 1 L8 [3.1 9.3

product, N-(2-hydroxy-n-hexadecyl)-iminodiacetic The Spangler-soil detergency tests are run using l5 acid, disodium salt, is recovered by the method depercent of each of the mentioned compounds, perscribed in Example l. The product is a white powder cent sodium tripolyphosphate and 50 percent sodium of similar characteristics to that produced by the sulfate, to make a textile-softening and detergent commethod of Example 1. 35 position. In these tests, the concentration of such wash- When the method of this example is followed, with ing preparation employed is 0.15 percent in water, the replacement of the hexadecane epoxide with other which corresponds to the recommended usage of such alkane-l,2-epoxides of 6 to 22 carbon atoms, corrematerials in ahome automatic washing machine. Three cotton percale swatches, each 3 inches by 6 inches, are

sponding iminocarboxylates are produced. In some first soiled with Spangler soil, which is a mixture of aircases, as with the longer chain epoxides, the reaction 40 conditions must be varied, as by increasing temperaborne and sebum soils. They are then washed in a Terture and using solvents and catalysts, to produce an gotometer evaluating washing machine, using waters of economically feasible reaction rate. In most cases howtwo different hardnesses, at two different temperatures,

ever, this is not necessary. Although it is normally deas indicated. After washing, the swatches are rinsed sirable to utilize the linear alkyl epoxides, the cycloaland are tested for whiteness, using a color difference kyl epoxides and the highly branched alkyl epoxides meter. The comparision of readings, using the Rd scale, may also be employed, as may be the slightly unsatubetween the materials before and after washing, is rated epoxides, such as the olefinic or dienic epoxides. made and the delta Rd is calculated. The greater the The products resulting are useful surface active agents delta Rd, the more efficient is the soil removal and the and in many cases possess exceptionally good textilebetter is the detergency obtained. Linear tridecyl bensoftening properties. zene sulfonate, as the sodium salt, isusually employed as a standard of comparison for detergency in this test.

EXAMPLE 3 From the data, as shown in Table 1, it is apparent that Although the products described in Examples 1 and the novel compounds tested, which are representative 2 possess general utilities as surface active agents, surof those made in accordance with this invention, as deface tension reducing agents, emulsifiers, detergents or scribed above, are useful detergents. They are effective softening agents for textiles, especially useful softening in hard water and water of medium hardness and in and detersive actions are noted for those compounds both hot and cold water, although they are most effecwherein R is of 12 to 20 carbon atoms. An especially tive in ordinary city water of medium hardness, such as useful compound of this type is N-( 2-hydroxyhex- New Brunswick tap water, and wash better in hot water adecyl)-iminodiacetic acid, disodium salt, which is repthan in cold water. Similar results are obtained by use resentative of the best such compounds. of the other iminodicarboxylates illustrated in the fore- When tested for efficacy as a fabric softener, N-(Z- going examples.

hydroxyhexadecyl)-iminodiacetic acid, disodium salt, The present invention has been described in conjuncobtains a rating of 10+, indicating an excellent softention with various illustrations and embodiments thereof ing effect on cotton materials. The test is run using oneset forth in the specification. However, it is evident that h lf f a r lmh r l i 3 ll f 1()() equivalents may be substituted for the present compounds and procedural steps, without departing from the principles of this invention or the spirit thereof. Those of skill in the art will recognize equivalents and substitutes that are also within the scope of the present disclosure.

What is claimed is:

l. A compound of the formula wherein R is alkyl of 12 to 20 carbon atoms, or alkenyl of 12 to 20 carbon atoms containing one or two ethylene double bonds, R and R are alkylene or arylene of 10 l to 9 carbon atoms and at least one of R and R is arylene and X and Y which may be the same or different are selected from the group consisting of hydrogen, alkali metal, ammonium, monoalkylamine, dialkylamine, trialkylamine, monoalkanolamine, dialkanolamine and trialkanolamine, in which the alkyl and alkanol groups are of l to 4 carbon atoms.

2. A compound according to claim 1 wherein R and R are phenylene and X and Y are the same.

3. A compound according to claim 1 wherein R is alkylene of l to 4 carbon atoms and R is phenylene.

4. A compound according to claim 1 wherein R is methylene and R is tolylene.

5. A compound according to claim 1 wherein R is phenylene and R tolylene. 

1. A COMPOUND OF THE FORMULA
 2. A compound according to claim 1 wherein R2 and R3 are phenylene and X and Y are the same.
 3. A compound according to claim 1 wherein R2 is alkylene of 1 to 4 carbon atoms and R3 is phenylene.
 4. A compound according to claim 1 wherein R2 is methylene and R3 is tolylene.
 5. A compound according to claim 1 wherein R2 is phenylene and R3 tolylene. 